Process for setting wool fabrics



Feb- 15, 1954 J. N. DALTON ET AL PROCESS FOR SETTING woorJ FABRICS Filed March Patented Feb. 16, i954 a PROCESS FOR SETTING WOOL FABRICS John N. Dalton, Providence, R. I., and william B. i Kaupin, Lawrence, Mass;, assignors to Pacific Mills, Lawrence, Massi, a corporation of Massa'- chusetts Y 'Application March z3, 1951, serial No. 217,292

This invention relates to a continuous -process for the permanent setting of wool fabrics, by which we mean fabrics of all wool or of mixtures of Wool, mohair, alpaca, etc.. ,with nylon, regenerated cellulose, cellulose acetate, Vicara, Fiber V (now known as Dacron), Orlon, etc. By permanent setting we mean resistant to boiling water for at least 1 hour as in subsequent dyeing and to steaming as in pressing. l

' A principal object of the invention is to provide a continuous, rapid and inexpensive process forfrfixing in a permanent and regular manner the warp and lling threads by the removal of r201mm.4 (Citas-76) all irregular and hidden strains while the fabric l is flat, .thus preventing-the formation of cockles, crimps, creases or otherforms of uneven shrinkage at later stages of manufacture, such as mill scouring, dyeing, finishing, steaming and sponging. A further object is to prevent movement in the warp and filling directions in the finished cloth, which is shown by shrinkage, bubbling, or puckering when the fabric is exposed to steaming or to elevated humidity as in pressing or cleaning. A further object is to provide a process of this character which is readily controlled. A further object is to avoid the defects of the conventional batch processes.

The most common operation now in use for setting wool fabrics is crabbing, with or without blowing Crabbing consists in winding the fabric under tension on a roller through boiling water. By this means the cloth is set but unless the work is carefully done many defects occur. The effectiveness of the process is governed by the tension at which the cloth is wound on the roller, the temperature and time of treatment, and the composition of the crabbing liquor. It is essential that each of these factors should be accurately controlled. The tension should be uniform but not too great or the handle of the fabric will be papery; the temperature of setting should be maintained constant; and the pH of the liquor 2 renders the fabric diicult to dye and subject to listing Then blown cloth dyes differently from unsteamedcloth and it is di'icult or impossible to obtain uniform results. Our process gives a set as good as or better than crabbing and blowing, but without these defects and disadvantages` and at lower cost.

In the accompanying drawing,

Fig. 1 is a schematic elevation partly in section of ,apparatus by means of which our process may be practiced, showing the part ofthe apparatus throughwhich the cloth is first passed, and

Fig. 2 is a similar schematic elevation of the remainder of the apparatus.,V y

According to our invention, the grey fabric, as itis continuouslyadvanced in open width, is first impregnated with an aqueous solution of pH range 9 to 12. The impregnating solution may be a buffered solution such as sodium hydroxide and disodium phosphate, sodium hydroxide and boric acid, etc., or it may be a solution of an organic derivative of ammonia such as an amine.

In our preferred practice the open fabric 2, which has not previously been wet with water, is passed through a three-roll mangle having a tank 4 containing the impregnating solution so that the fabric is given two dips and two nips. The squeezed fabric retains more than 20%, and preferably about 50% to 60%, of its weight of the impregnating liquor after the final nip. The impregnated fabric is passed under a dancer roll 6 where the warp tension is adjusted and then fed onto a tenter at 8. The fabric on the tenter, adjusted with tension to the proper width, is so heated throughout its thickness that steam is generated in the interior of the fabric which coacts with the liquid in the fabric to set the yarns of the fabric.

To provide such heating we prefer to pass the fabric between banks of infra-red lamps l0, l2, over and under the traveling fabric.

For best results we use an upper bank l0 of 565 lamps and a lower bank I2 of 625 lamps, which banks are spaced 14 inches apart with the cloth in the middle. The banks are about 8 yards long on the tenter and are of su'icient width to cover the fabric, which generally is 5 feet wide. The fabric travels at a speed of 25 to 35 yards a minute and thus is maintained between the banks of lamps for from about 21 to 14 seconds. The lamps are 375 watts each, making a total of about 446 kilowatts, and providing over 25,000 B. t. u. per minute. Thus the cloth traveling at 25 yards per minute receives a heat input Blowing always lowers the tensile strength and of over 67 B. t. u. per square foot and when traveling at 35 yards per minute a heat input of over 48 B. t. u. per square foot. The number or size of the lamps may be varied to give a heat input between about 15,000 and 35,000 B. t. u. per minute.

The fabric passes out of the tenter while `still damp and containing more than 20%, preferably 20% to 25%, of its weight of the impregnating liquor.

The fabric is then scoured in a continuousl Washer I4.

Our process has many advantages in the ease' with which it may be controlled` The pH of the impregnating liquid is easy vte regulate.v The amount of pickup of such liquid can be: readily controlled. The number of lamps in the banks in the tenter may be varied aswell asthe speedA of the fabric through the tenter thereby controlling the generation of steam throughout the'f damp fabric. The dampness or moisture content of the fabric as-it comes from the tenter may likewisefbe readily controlled. Both Warp and weft tension may be independently controlled; In these particulars our process hasr great practical advantages over the batch processes for setting Wool fabrics now in use.

We claim:

1. A continuous process for imparting to Wool fabrics a permanent set resistant to-mi1l scouring, dyeing, finishing, steaming and sponging which comprises continuously advancing the fabric in open width, wetting thetraveling fabric by= impregnating it with an aqueous solution of pH 9 to 12, subjecting the wet traveling fabric from both sides for about 14 to 21 seconds to high' intensity infra-red radiation tov generatesteam in the interior of the fabric, while maintaining said fabric under Warpwise and weftwise tension, discontinuing application of infra-red radiation While the fabric contains more than 20% of its weight of the impregnating liquor, and thereafter scouring the fabric in a continuous washer.

` 2. A continuous proces's fr imparting to wool fabrics a permanent set resistant to mill scouring, dyeing, finishing, steaming and sponging which comprises continuously advancing the fabric in open Width, wetting the traveling fabric by impregnating it with an aqueous solution of pH 9 to 12,` generating steam in the interior of the wet traveling. fabric for'about 14 to 21 seconds to coact withtheliquid in the fabric to set the yarns of the fabric, while'infaintaining said fabric under warpwise and weftwise tension, discontinuing the generation of' steam `while the fabric contains more than.l 20% of the weight of the impregnating liquor, and thereafter scouring the fabric in a continuous washer. A Y

Referencesl Cited in the le of this' .patent UNITED STATES' PA'IENTS Nur'nbeny Nam 2,132,1561 Gessn'er ,cuuclsf 2,251,127 Gessner Jurylz; 1914-1 2,3'193653y Ridley July 3'; 1955 2,499,444' n11isQnf -v s Mr. 7; rq 1508x107 Block et a1 g Mayra, '1950' FOREIGN PATENTS 546,529V Great Britain Juli/173.1942 

